Hartleton is a borough in Union County, Pennsylvania, United States.

Kester's was at the intersection of "great Reuben Haines road" from Northumberland through Dry Valley, New Berlin and the Penns Valley Narrows, and the first public road laid out in the area by Northumberland County court from Northumberland through Derrstown (Lewisburg) and Mifflinburg (this road from Derrstown through the Penns Valley Narrows eventually became what is known as the turnpike).

Hartley never lived there, as his home was in York, PA. Hartley acquired the land in 1784 from original purchaser Colonel Philip Cole after Cole left the area because of the "Big Runaway" of 1778.

[5] According to the United States Census Bureau, the borough has a total area of 0.9 square miles (2.3 km2), all land.

19.1% of all households were made up of individuals, and 14.6% had someone living alone who was 65 years of age or older.